<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org" lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    html, body {
        height: 100%;
        margin: 0;
        padding: 0;
        overflow: hidden; /* 防止滚动条出现 */
    }

    iframe {
        width: 100%;
        height: 100%;
        border: none; /* 移除边框 */
    }
</style>
<body>
<div style="height: 50px">
    <h1 th:text="'欢迎'+${message}"></h1>
</div>
<div style="height: 100%">
    <iframe src="http://xiaohongqi3d.cn/"></iframe>
</div>

</body>
</html>